Hitherto, various types of devices for delivering a fixed quantity of liquid have been developed; for example, (1) an air type delivering device in which compressed air is applied under regulated pressure to a liquid in a reservoir vessel for a predetermined time such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end, (2) a plunger type delivering device in which a plunger is liquid-tightly disposed with respect to a liquid in a reservoir vessel and is moved to pressurize the liquid such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end, and (3) a multi-plunger pump type delivering device having a mechanism in which a cylinder is disposed between a reservoir vessel and a nozzle, a plurality of penetration holes are formed in the cylinder and receive plungers in a one-to-one relation to be able to advance or retreat, and the liquid is sucked into the cylinder from the reservoir vessel with the retreat of the plunger and is delivered from the cylinder to the nozzle with the advance of the plunger, the plurality of plungers acting upon the liquid in sequence to pressurize the liquid such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end.